Method, system and apparatus for processing fibril cellulose and fibril cellulose material

Abstract

The invention relates to a method for processing chemically modified fibril cellulose. The method includes introducing chemically modified fibril cellulose material to a thermal drying device including a belt in such a way that the fibril cellulose material forms at least one bar onto the belt, and dewatering the chemically modified fibril cellulose material on the belt using heated air flow having a temperature of at least 40 ° C. in order to concentrate and/or dry the chemically modified fibril cellulose material in such a way that the dry solids content of the fibril cellulose material after the thermal drying device is at least 10%. In addition, this invention relates to a thermal drying device, a system for processing chemically modified fibril cellulose, a method and a system for redispersing the fibril cellulose, and a fibril cellulose material.

The invention claimed is: 
     
       1. A method for processing chemically modified fibril cellulose, comprising
 introducing chemically modified fibril cellulose material to a thermal drying device comprising at least two belts and at least one crushing device in such a way that the fibril cellulose material forms at least one bar onto the first belt, 
 crushing the chemically modified fibril cellulose material in the crushing device after the bar formation onto the first belt, 
 drying and/or concentrating the chemically modified fibril cellulose material on the second belt after, the crushing step, and 
 dewatering the chemically modified fibril cellulose material on at least one of the at least two belts using heated air flow having a temperature of at least 40° C. in order to concentrate and/or dry the chemically modified fibril cellulose material in such a way that the dry solids content of the fibril cellulose material after the thermal drying device is at least 10%. 
 
     
     
       2. The method according to the  claim 1 , wherein the first belt is a wire and at least part of the heated air flows through the first belt. 
     
     
       3. The method according to the  claim 1 , wherein a viscosity of the fibril cellulose introduced to the thermal drying device is at least 10000 mPas in a supplying consistency of said fibril cellulose, wherein dry matter content of said fibril cellulose is between 0.5-9%. 
     
     
       4. The method according to the  claim 1 , wherein fibril cellulose material on the first belt of the thermal drying device covers at least 30% of the drying area of the first belt. 
     
     
       5. The method according to the  claim 1 , further comprising
 supplying the chemically modified fibril cellulose material to a feeding tank, 
 conveying the chemically modified fibril cellulose material from the feeding tank to the thermal drying device, wherein a mono pump is used in the conveying process. 
 
     
     
       6. The method according to the  claim 1 , further comprising
 extruding the chemically modified fibril cellulose material onto the first belt by a nozzle forming the bar. 
 
     
     
       7. The method according to the  claim 1 , wherein the bar is in the form of a string, and there are several strings on the first belt, each of the strings having a diameter between 2 and 10 mm. 
     
     
       8. The method according to the  claim 1 , wherein the bar is in the form of a layer comprising clippings, and a thickness of the layer is between 5 and 20 cm. 
     
     
       9. The method according to the  claim 1 , wherein the bar is in the form of a single layer. 
     
     
       10. The method according to the  claim 1 , wherein the heated air is generated by means of a heat exchanger from waste heat of a pulp mill, steam or electric power. 
     
     
       11. The method according to the  claim 1 , further comprising
 pre-drying the chemically modified fibril cellulose in a pre-drying device prior to the thermal drying device in such a way that the dry matter content of the fibril cellulose introduced to the thermal drying device is at least 5%. 
 
     
     
       12. The method according to the  claim 1 , comprising following said dewatering,
 introducing said chemically modified fibril cellulose material having a dry solids content of at least 10% to a hydration device, 
 redispersing the chemically modified fibril cellulose into liquid in an dispergator in order to achieve chemically modified fibril cellulose having a dry matter content between 0.01and 5%. 
 
     
     
       13. The method according to the  claim 12 , further comprising
 wetting the chemically modified fibril cellulose material having a dry solids content of at least 10% in the hydration device, and 
 conveying the wetted chemically modified fibril cellulose material to the dispergator. 
 
     
     
       14. The method according to the  claim 12 , wherein the redispersed fibril cellulose has the zero shear viscosity of 1000 to 50000 Pas and yield stress of 1-30 Pa. 
     
     
       15. The method according to the  claim 12 , wherein the fibril cellulose will give, when redispersed in water, viscosity that is at least 60%.